Workaround to be implemented to recover the environment after the issue has occurred

1. Identify all the ports that are in a Blocked state, by running the below command
net-dvs -l | grep -E "port |port.block|volatile.vlan|volatile.status"
2. Identify the port IDs for all connected interfaces on the ESXi host
net-stats -l
3. Match the output of 2 and 3 to see what ports correspond to which vNic interfaces
4. Identify the N-VDS switch name on the host
esxcfg-vswitch -l
5. Run below command to unblock the ports which are in blocked state
net-dvs -s com.vmware.common.port.block=false <N-VDS-NameFromStep4> -p <LogicalSwitchPor UUIDfromStep1>
Example:
net-dvs -s com.vmware.common.port.block=false N-VDS-hostswitch -p c2602212-cec6-4783-865a-2e9ae8fe6a71
6. In a rare event, the VLAN of the port maybe lost as well. To re-add the VLAN back, run:
net-dvs -v <VLAN-ID> -p <LogicalSwitchPortUUIDfromStep1> <N-VDS-NameFromStep4>
Example:
net-dvs -v 2081 -p c2602212-cec6-4783-865a-2e9ae8fe6a71 N-VDS-hostswitch

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Workaround to be implemented to increase the timeout from 24 hours (1 day) to 100 days.

Note: 
- This will delay the host disconnect issue by 100 days, if the host reconnects within 100 days the issue will not be seen.
- The workaround will NOT be useful for the hosts which have already been disconnected and CCP has expired the host data.
             
1. Login as root on the controllers.
2. vi /opt/vmware/ccp/bin/java/vnetcontroller/core.properties
3. Search for the following line in the core.properties file
            “connection.expire.period=<expiry-time-in-minutes>”
4. If this parameter is not present in core.properties, add the following line to increase timeout from 1 day to 100 days. The default value is 1440 minutes or 24 hours or 1 day
              “connection.expire.period=144000”
5. If this parameter is present in core.properties, modify the timeout value from 1440 to 14400
6. Restart the controller service (login as admin and run “restart service controller”)